jeudi 9 février 2012

Maven BuildNumber plugin - short revision id for Git

Today, I would like to explain the improvement for maven plugin - buildNumber, that I talked in my previous message - short revision id for Git SCM.

IMPORTANT : This feature is present in the maven-buildnumber-plugin 1.1 version.

You can specify the length for the Git revision. To enable this feature you have to specify the new tag
in the
section. For exemple:

The associated maven output informs us about the detection of shortRevisionLength tag and print the length of the revision that will be used in buildNumber formatting:

Some implementation details

This feature uses internally the git rev-pasre --short (see associated git help section) command and the revision length is set to minimum 4 characters. So you can't have the revision id shorter then 4 characters. Even if you specify the length between 0 and 4, the plugin will inform you about this situation and the minimum value (4) will be used.

UPDATED: If your maven build can't find the dependency for maven-buildnumber-plugin 1.1 , try to force the dependency update  by adding option "-U" for your mvn command.

mercredi 8 février 2012

My first Open Source commitment - Git short revision

Today, my patches for 2 maven projects have been accepted by the maven-buildNumber-plugin's project lead Olivier Lamy.

One of the web Java project, I currently working on, is fully automated with Maven. One interesting and useful thing is to have the date & the revision number at the bottom of the web page. Like this:
It was done with excellent maven plugin buildNumber -

The problem was that the project SCM migrated from the SVN to Git. And the revision ID in Git is too long. In fact it's SHA-1 sequence that should be unique across the world and all possible revisions... So the build id at the bottom of the page was so ugly for business users that I receive the task to make it shorter.

After asking the question about the git short revision id in and in the user's mailing lists of the maven, I understood that the buildNumber plugin does not support this feature. And the project Lead, Olivier Lamy, gracefully proposed to me to make a patch and pointed out the first java class I have to look at.
The code he sent me was very clear and I quickly figured out how to add the new feature that I called shortRevisionLength.
After one day of working I have sent the patch to Olivier and created 2 issues on the codehouse JIRA server:
I added some test cases and the documentation patch as well.

The next day the patch has been approved and integrated in the SVN. So, the next version of buildNumber plugin 1.1 contains some peace of code from Ukraine :) Nice.